Problem started the afternoon of 4/18/14.
I do show signal (4 bars) and can send and receive texts.
When i try to call out i get an error message on the screen that says network busy.
It worked today on the 4/19/14 about 4 miles from my house.
All four of the phones on our plan have the same problem. We live right next to each other.
We have tried resetting all the phones by removing the batteries. Didn't help. Can you?